find_flood_drought: Detect floods and droughts based on Mckee et al. (1993)
In ErickChacon/mbsi: Model-based Standardized Index

Description Usage Arguments Details Value Author(s) Examples

find_flood_drough detect events of floods and droughts based on the definition proposed by Mckee et al. (1993) using a time series of standardized precipitation values. A drought (flood) is defined as a period of time in which the SPI is continuously negative (positive) reaching at least one value lower (higher) or equal to -1 (1).

1 2	find_flood_drought(spi, threshold = qnorm(1 - 0.05/2), labels = c("normal", "drought", "flood"))

`spi`	A vector representing the time series of the standardized values.
`threshold`	An numeric value used to detect the extreme events, 1 (-1) is used by default as proposed by Mckee et al. (1993).
`labels`	A character vector providing the labels used to return the three types of events `normal`, `drought` and `flood`.

Although the definition of Mckee et al. (1993) uses a threshold of 1 (-1). Other values can be used for this threshold.

A factor vector indicating the time of event the standardized precipitation value corresponds.

Erick A. Chacon-Montalvan

data(simrain)
# Compute standardized values
spi_rain <- mbsi(simrain$rain, simrain$time)
# Identify floods and droughts
spi_rain$event <- find_flood_drought(spi_rain$spi, threshold = 2)
spi_rain$event